My theory is that it came out of a bezel. It's hard to think of why some investor was "carrying around his coin". So I theorize a jewelry loss.
But hey, anything's possible. People could be carrying coins from their coin-collection. I knew a guy who found a seated quarter , on the beach-dry sand, that he knew was a recent non-jewelry loss. Why ? Easy : It was still in the plastic sleeve with the coin-store price tag still on it. Doh ! Apparently some tourist had just bought it at this tourist-towns coin-store. Then promptly went to the beach and lost it. Doh !